Carlo Ancelotti could be entering his final season as Bayern Munich head coach according to former captain Stefan Effenberg, who also implored the club to retain the services of Thomas Muller.

The Italian led Bayern to a fifth successive Bundesliga crown in his first season at the Allianz Arena but also oversaw the club's earliest Champions League exit since 2010-11, losing to Real Madrid in the quarter-finals.

Bayern have suffered defeats at the hands of Arsenal, AC Milan, Inter, Liverpool and Napoli over the course of their pre-season schedule, and Effenberg believes Ancelotti may not be around much longer if he cannot improve on last term.

"If the season unfolds like the last one or perhaps even worse, it's possible," he told T-Online. "Players are exchanged at Bayern and maybe the coach also sometimes."

Effenberg also criticised the players' performances, adding: "I have missed players who play for and with each other so far in the pre-season.

"For me, desire is the most important thing in football. If some players lack the will, then I have to worry.

"But we also know that, when Bayern are hit and wounded, they can always fight back against any opponent."

Bayern have bolstered their squad with the arrival of the likes of James Rodriguez and Corentin Tolisso during the close-season, prompting some debate over how much first-team action Ancelotti will afford club great Muller this campaign.

"So many things can happen in a season - injuries, suspensions," Effenberg commented. "A lot of things sort themselves out.

"If, however, Ancelotti is drawing on a full squad, there are decisions that may hurt one or the other.

"It is to be assumed that it could be Franck Ribery or Thomas Muller at times, because Ancelotti has brought in his own players and they will surely be given the chance first.

"For great coaches - and Ottmar Hitzfeld perfected this - you have to keep the balance and to keep the players on the bench content.

"If that happens, Bayern will march on. If not, it will be a restless season."

Asked whether Muller should leave the club, Effenberg said: "No, why? He is the face of Bayern Munich, after the departures of [Bastian] Schweinsteiger and [Philipp] Lahm.

"Bayern would be making a huge mistake in letting him go. He has played for many years at an incredible level."